Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/002—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by condensation
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D5/00—Condensation of vapours; Recovering volatile solvents by condensation
  • B01D5/0078—Condensation of vapours; Recovering volatile solvents by condensation characterised by auxiliary systems or arrangements
  • B01D5/0093—Removing and treatment of non condensable gases
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01D—SEPARATION
  • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
  • B01D53/26—Drying gases or vapours
  • B01D53/263—Drying gases or vapours by absorption
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
  • Y02A20/00—Water conservation; Efficient water supply; Efficient water use
  • Y02A20/124—Water desalination

Definitions

• the present invention relates to a method and apparatus for separating non-condensable gases from vapor by isother ⁇ mal absorption. It is thereby possible to intensify the deaeration of condensers and to decrease the amount of pumping energy required.
• entrained non-condensable gases are separable from the vapor in the condenser by cooling the mixture of the .vapor and gases entrained therewith.
• the vapor pressure reduces while the partial pressure of the non-condensable gases rises. In this manner, the portion of vapor in the mixture is decreased, which reduces the total amount of gas to be pumped away from the underpressure in connection with deaeration.
• the condenser designed for cooling of vapor has to meet exacting demands to ensure that the flow velocity of the gas mixture is maintained sufficient in order to prevent the accumulation of non-condensable gases and to keep the flow losses small enough. If the gas mixture is cooled, for example, by 2°C from 25°C, the vapor pressure will reduce from 31.7 mbar to 28.1 mbar. If the total pressure at the same time reduces by 1 mbar because of flow losses, the partial pressure of the non-condensable gases will be 2.6 mbar. In this case, over ten times of the flow volume of vapor has to be removed with non-condensable gases.
• the partial pressure of the non- condensable gases can be raised by means of isothermal absorption.
• the gas mixture discharged from the condenser can be brought into contact with an absorption medium, in which medium the vapor pressure is low in comparison with the vapor pressure in the gas mixture.
• absorption mediums can serve aqueous solutions of several well soluble salts such as, for example, sodium hydroxide, lithium- bromide, lithium chloride, calcium chloride, potassium carbonate and potassium acetate.
• Vapor 16 of some process is condensed in a condenser 10, and the flow 17 of non- condensable gases of the vapor and the vapor entrained with said non-condensable gases then flow to an absorber 11, in which they come into contact with an absorption maxim .
• the absorption medium When absorbing to a solution, vapor gives its absorption heat to said solution, whereby the temperature of the solution tends to rise and the vapor pressure thereof tends to increase correspondingly.
• the absorption medium is cooled in an indirect heat transfer means 22 by a coolant such as, for example, cooling water, similarly to the coooling in the absorber of an absorption heat pump.
• a coolant such as, for example, cooling water
• the absorption medium is, for example, a solution of 30% sodium hydroxide at a temperature of 25°C
• the vapor pressure thereof is about 14 mbar.
• the partial pressure of non- condensable gases will rise to 16.7 mbar. Only 0.8 of the flow volume of vapor has to be removed with non-conden ⁇ sable gases in this case. This essentially reduced gas flow 18 is removed from the absorber by some previously known pumping method 14.
• the absorption medium is diluted when vapor absorbs there ⁇ into. It is concentrated by vaporizing a corresponding amount of vapor from this absorption medium at a slightly higher temperature.
• the absorption medium is pumped by pump 15 into the vapor generator 12, in which vapor generator an amount of vapor corresponding to the absorbed amount of water is vaporized from said absorption medium at a higher temperature by heating the medium through a heat exchanger 21 in a manner similar to that used in the vapor generator of an absorption heat pump.
• the released vapor can be condensed in a separate condenser 13.
• the temperature can also be so regulated that the pressure of the releasing vapor equals that of the original, absorbed vapor, in which case this revaporized vapor 20 can be condensed in the same condenser 10 from which the mixture of the vapor and non-condensable gases was removed.

Landscapes

• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Engineering & Computer Science (AREA)
• Analytical Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Sorption Type Refrigeration Machines (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8527485

Family Applications (1)

Country Status (5)

Cited By (1)

Citations (2)

• 1988
  • 1988-11-29 FI FI885530A patent/FI81967C/sv not_active IP Right Cessation
• 1989
  • 1989-11-22 WO PCT/FI1989/000214 patent/WO1990006163A1/en not_active Application Discontinuation
  • 1989-11-22 EP EP89912819A patent/EP0446229A1/en not_active Withdrawn
  • 1989-11-22 AU AU46213/89A patent/AU4621389A/en not_active Abandoned
  • 1989-11-28 CA CA002004032A patent/CA2004032A1/en not_active Abandoned

Patent Citations (2)

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